The lithium secondary battery whose negative electrode is formed by using a material capable of occluding and releasing lithium ions is capable of restraining the precipitation of dendrite to a higher extent than a lithium battery whose negative electrode is formed by using metallic lithium. Therefore the lithium secondary battery has been supplied to the market as a battery having enhanced safety. In recent years, the lithium secondary battery is developed for driving vehicles. Thus it is a big problem to allow the lithium secondary battery to have energy regeneration, namely, quick charging performance. As a countermeasure for this problem, the following (1) and (2) are considered: (1) decrease of electric resistance of the battery, (2) prevention of precipitation reaction of metallic lithium in intercalation and deintercalation reactions of lithium ions and quick progress of the intercalation and deintercalation reactions. Regarding the above-described (1), to thin positive and negative electrodes and devise the construction of a current collection foil to decrease the electric resistances of the electrodes are proposed (see patent document 1). Further the following proposals are made: to increase the amount of conductive materials inside the electrodes to decrease the electric resistance thereof and to lower the electrical resistance of a separator. Regarding the above-described (2), the following proposals are made: to increase the specific surface area of active substances of positive and negative electrodes, to increase the areas of the electrodes to decrease the density of charging and discharging currents, and to alter the active substance of the negative electrode from a graphite material to an amorphous carbon material or lithium titanate.
These devices make it possible to improve quick charging performance. But the alteration of the negative electrode material of the above-described (2) is disadvantageous in allowing the battery to have high capacity. To use the battery for vehicles, a little improvement of the performance thereof is insufficient, but there is a demand for the development of the battery which can be fully and quickly charged, for example, within one minute. This is because the battery for use in vehicles is desired to have a large or high capacity to gain distance to electrically drive vehicles. But as a result of an increase in the weight of the battery, it is difficult to improve the travel distance of vehicles. To solve the problem, by improving the regenerative performance of the battery to a high extent without increasing the capacity thereof and by fully charging the battery within one minute, the vehicle can be electrically driven when the battery can be regenerated in a very short period of time, even though the capacity thereof is exhausted owing to discharge. In the case where the battery can be fully charged within one minute it is possible to instantaneously charge the battery of electric cars at a charging station, which is very advantageous.